Non-Viral Gene Delivery to Mesenchymal Stem Cells: Methods, Strategies and Application in Bone Tissue Engineering and Regeneration

Abstract

Mesenchymal stem cells (MSCs) can be isolated from several tissues in the body, have the ability to self-renewal, show immune suppressive properties and are multipotent, being able to generate various cell types. At present, due to their intrinsic characteristics, MSCs are considered very promising in the area of tissue engineering and regenerative medicine. In this context, genetic modification can be a powerful tool to control the behavior and fate of these cells and be used in the design of new cellular therapies. Viral systems are very effective in the introduction of exogenous genes inside MSCs. However, the risks associated with their use are leading to an increasing search for non-viral approaches to attain the same purpose, even if MSCs have been shown to be more difficult to transfect in this way. In the past few years, progress was made in the development of chemical and physical methods for non-viral gene delivery. Herein, an overview of the application of those methods specifically to MSCs is given and their use in tissue engineering and regenerative medicine therapeutic strategies highlighted using the example of bone tissue. Key issues and future directions in non-viral gene delivery to MSCs are also critically addressed.

Liposomes in tissue engineering and regenerative medicine

“…RNAi may be a possible alternative to guide stem cells' fate without incorporation of pDNA into the host cells' genome. Cationic liposomes are a possible alternative to transfect cells, but they have a lower transfection efficiency [169]. The combination of liposomes with scaffolds represents a good approach to overcome this limitation.…”

“…Thus, when stem cells are used to correct a genetic pathology and to express the therapeutic gene for the duration of a patient's life, viral vectors are preferred [169]. Conversely, when stem cells are used to treat non-inherited diseases and are only required to express the therapeutic gene for a short period of time, non-viral vectors are preferred [169]. Although viral vectors are more efficient, they possess some limitations such as high production cost, safety issues including mutagenesis, the immunogenicity of the virus proteins, lack of desired tissue selectivity and generation of infectious viruses due to recombination [170][171][172].…”

Scaffold‐Based microRNA Therapies in Regenerative Medicine and Cancer

“…[38,39,52] This temporality can be advantageous for numerous RM applications, where time-span limit of the therapeutic is of utmost importance, and a maintained effect after tissue regeneration may be highly detrimental. Additionally, high-mass production of nonviral methodologies tends to be less complex and costly than that of viral vectors.…”

“…Additionally, high-mass production of nonviral methodologies tends to be less complex and costly than that of viral vectors. [52] Several cationic polymers are commercially exploited for miRNA delivery at a research level, while innovations in the nanotechnology arena increasingly continue to introduce interesting alternatives. Cationic lipids are among the most commonly utilized nonviral vectors for gene therapy applications.…”

Non-viral gene-activated matrices

“…Considering the concerns associated with using viral vectors and as transient gene expression is such a key consideration, many researchers would agree that non-viral vectors should be the primary choice for GT applications in TE. 33,34 Non-viral vectors are designed to essentially mimic the cell-entry abilities of their viral counterparts. 35 Non-viral gene transfer methodologies offer several advantages, all of which are independent to individual vectors.…”